I'd have noticed any of these around!I was very attracted to the Hortensja pieces and bought a couple - without knowing what they were, just because they are so lovely. I gave the brown on to a friend who broke their piece but kept my blue goblet.(pics attached)

I do think your piece is even more attractive than the Hortensja bits I've seen - I haven't seen many.

Mine weighs about 250g; the rim and walls are really thin (less than 1 mm glass thickness), but the base section is rather heavy.So mine could be Hortensia as well, I guess -- if several Polish companies used this technique.

I think there has gone some effort in this piece, bevelling such a delicate rim...